Near the end of the game, equip an Elemental Spirit then speak to it in the Mana Village. Successfully complete its quest to meet the Benevodon of the same element in another dungeon. Do the same thing for the other seven Elemental Spirits to get a total of eight Lex items. Successfully complete the game after you have done this. When the game resumes at the Mana Village, the Mana Tree mural will glow. Enter it to teleport to a bonus section of the last dungeon.